This invention relates to a method of producing polyurethane foams.
In a particular aspect, this invention relates to a method of producing polyurethane foams by using a substituted imidazoline as a catalyst therefor.
Catalysts for curing polyurethane foams prepared from isocyanates and polyols to produce rigid objects are well-known and are used commercially in large quantities. Such catalysts should be free from hydroxy groups and primary and secondary amine groups because these groups are reactive with the isocyanates. In addition to being non-reactive, a suitable catalyst should promote curing at a rapid rate. While several stages of curing are involved, the most important is the time required to produce a firm foam, for that determines the length of time the foam remains in the mold, and hence the production rate for any given mold. Presently used catalysts, while satisfactory, are expensive and consequently a catalyst having a lower cost or lower firm time is needed in the art.